Multipath driver cognitive analysis

Abstract

An aspect includes detecting a recurring intermittent error in a path of a network in a system that includes at least one data transmission port configured for connection to at least one shared data storage device via a plurality of paths of the network. It is determined whether a cause of the recurring intermittent error is a previous path recovery action. In response to determining that the cause of the recurring intermittent error is not a previous path recovery action, the data transmission port is prevented from accessing the path for a specified time period by moving the path into a degraded sub-state, and subsequent to the specified time period the data transmission port is provided access to the path. In response to determining that the cause of the recurring intermittent error is a previous path recovery action, the data transmission port is provided access to the path.

What is claimed is: 
     
       1. A system for transmitting data in a network, the system comprising:
 at least one data transmission port configured for connection to at least one shared data storage device via a plurality of paths of the network; 
 a memory having computer readable instructions; and 
 a processor for executing the computer readable instructions, the computer readable instructions including:
 detecting a recurring intermittent error in one of the paths of the network; 
 determining whether a previous recovery action was performed on the path; 
 in response to determining that a previous recovery action was not performed on the path:
 preventing the data transmission port from accessing the path for a specified time period by moving the path into a degraded sub-state, wherein the specified time period is based on a number of paths of the plurality of paths being accessible to the data transmission port as usable paths; and 
 providing the data transmission port access to the path subsequent to the specified time period; and 
 
 in response to determining that a previous recovery action was performed on the path:
 providing the data transmission port access to the path. 
 
 
 
     
     
       2. The system of  claim 1 , wherein the instructions further include:
 determining whether to use a previously selected reserved path of the plurality of paths or an other one of the plurality of paths to perform an input/output (I/O) operation to the at least one shared storage device, wherein the other path is selected to perform the I/O based on the reserved path being in the degraded sub-state and the other path not being in the degraded sub-state. 
 
     
     
       3. The system of  claim 1 , wherein the instructions further include:
 determining whether to perform a last gasp health check on the path; 
 performing the last gasp health check on the path based on the path being the last path in the plurality of paths that is not failed and a cause of the previous recovery action being a condition other than a unit attention (UA) indicator from one of the at least one shared data storage device; and 
 skipping the last gasp health check on the path based on the cause of the previous recovery action being a UA indicator from one of the at least one shared data storage device. 
 
     
     
       4. The system of  claim 1 , wherein the specified time period is further based on a number of successful health checks being performed on the path subsequent to the preventing. 
     
     
       5. The system of  claim 1 , wherein the computer instructions further include:
 subsequent to the preventing and prior to the providing:
 issuing health checks on the path; 
 determining that a specified number of the health checks were successful; 
 issuing an I/O on the path; and 
 determining that the I/O was successful, wherein the providing the data transmission port access to the path is further based on determining that the I/O was successful. 
 
 
     
     
       6. The system of  claim 1 , wherein the network is a storage area network. 
     
     
       7. A method comprising:
 detecting, by a processor, a recurring intermittent error in a path of a network in a system that includes at least one data transmission port configured for connection to at least one shared data storage device via a plurality of paths of the network; 
 determining whether a previous recovery action was performed on the path; 
 in response to determining that previous recovery action was not performed on the path:
 preventing the data transmission port from accessing the path for a specified time period by moving the path into a degraded sub-state, wherein the specified time period is based on a number of paths of the plurality of paths being accessible to the data transmission port as usable paths; and 
 providing the data transmission port access to the path subsequent to the specified time period; and 
 
 in response to determining that a previous recovery action was performed on the path:
 providing the data transmission port access to the path. 
 
 
     
     
       8. The method of  claim 7 , further comprising:
 determining whether to use a previously selected reserved path of the plurality of paths or an other one of the plurality of paths to perform an input/output (I/O) operation to the at least one shared storage device, wherein the other path is selected to perform the I/O based on the reserved path being in the degraded sub-state and the other path not being in the degraded sub-state. 
 
     
     
       9. The method of  claim 7 , further comprising:
 determining whether to perform a last gasp health check on the path; 
 performing the last gasp health check on the path based on the path being the last path in the plurality of paths that is not failed and a cause of the previous recovery action being a condition other than a unit attention (UA) indicator from one of the at least one shared data storage device; and 
 skipping the last gasp health check on the path based on the cause of the previous recovery action being a UA indicator from one of the at least one shared data storage device. 
 
     
     
       10. The method of  claim 7 , wherein the specified time period is further based on a number of successful health checks being performed on the path subsequent to the preventing. 
     
     
       11. The method of  claim 7 , further comprising:
 subsequent to the preventing and prior to the providing:
 issuing health checks on the path; 
 determining that a specified number of the health checks were successful; 
 issuing an I/O on the path; and 
 determining that the I/O was successful, wherein the providing the data transmission port access to the path is further based on determining that the I/O was successful. 
 
 
     
     
       12. The method of  claim 7 , wherein the network is a storage area network. 
     
     
       13. A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by processing circuitry to cause the processing circuitry to perform:
 detecting a recurring intermittent error in a path of a network in a system that includes at least one data transmission port configured for connection to at least one shared data storage device via a plurality of paths of the network; 
 determining whether a previous recovery action was performed on the path; 
 in response to determining that a previous recovery action was not performed on the path:
 preventing the data transmission port from accessing the path for a specified time period by moving the path into a degraded sub-state, wherein the specified time period is based on a number of paths of the plurality of paths being accessible to the data transmission port as usable paths; and 
 providing the data transmission port access to the path subsequent to the specified time period; and 
 
 in response to determining that previous recovery action was performed on the path:
 providing the data transmission port access to the path. 
 
 
     
     
       14. The computer program product of  claim 13 , wherein the program instructions further cause the processor to perform:
 determining whether to use a previously selected reserved path of the plurality of paths or an other one of the plurality of paths to perform an input/output (I/O) operation to the at least one shared storage device, wherein the other path is selected to perform the I/O based on the reserved path being in the degraded sub-state and the other path not being in the degraded sub-state. 
 
     
     
       15. The computer program product of  claim 13 , wherein the program instructions further cause the processor to perform:
 determining whether to perform a last gasp health check on the path; 
 performing the last gasp health check on the path based on the path being the last path in the plurality of paths that is not disabled and a cause of the previous recovery action being a condition other than a unit attention (UA) indicator from one of the at least one shared data storage device; and 
 skipping the last gasp health check on the path based on the cause of the previous recovery action being a UA indicator from one of the at least one shared data storage device.